Digital Archiving

There are tools to combat this. Please post your own tips and techniques.

General page archiving: https://addons.mozilla.org/en-us/firefox/addon/shelve/
Shelve can be configured to automatically save every page you visit. Each version is saved in a timestamped folder under the domain name (in your Firefox profile folder).
Recommended file name template: %{shelvedir}%/%B%/%Y-%M-%D-%h-%m-%s-%l%/%[ctF]%e